Pneumatic power hammer



H. F. MASSEY PNEUMATIC POWER HAMMER Filegl Ju1y 26, 1922 5 Sheets-Sheet 1 Jan. 27; 1925 1,524,195

v H. F. MASSEY PNEUMATIC POWER HAMMER Filed July 26, 1922 5 Sheets-$heet 4 0 9 as 59 15 g 51 57 52 22 0'\ v {5 i Y \j .J7z2/e 2@7xflaw R 1,524,195- H. F. MASSEY PNEUMATIC POWER HAMMER Patented Jan. 27, 1925, l 1.

UNITED STATES PATENT OFFICE.

HAROLD FLETCHER MASSEY, or DISLEY, ENGLAND.

PNEUMATIC POWER, HAMMER.

Application filed July 26, 1922. Serial No. 577,601.

To all whom it may concern:

Be it known that I, HAROLD FLETCHER Mnssnr, a subject of the King of the United Kingdom of Great Britain and Ireland, and resident of Glenanore, Disley, in the county of Chester, England, have invented new and useful Improvements in Pneumatic Power Hammers, of which the following is a specification.

The invention refers to pneumatic power hammers of the double acting reciprocating air current type.

In such hammers as most commonly made the striking of single blows is difficult. They can most easily be struck from the position in which the hammer rests on the anvil, but even so there is need of care and skill in handling the hammer and the blow obtained is not a full power blow.

In some other hammers arrangements have been made for striking single blows but these have necessitated the use of further mechanisms such as relief devices, automatic blow off devices etc., which have added considerable complication to the mechanism.

The object of the present invent-ion is to improve the control of pneumatic power hammers of the type mentioned and particularly to give facilities for striking single blows by a method which adds no appreciable complication to the mechanism, and makes it practicable to obtain single blows of full power by simple and easy manipulation of the controlling devices.

The ability to strike such single blows when desired and alternatively the self acting blows renders the hammer much more efficient and adaptable to various classes of work than hammers hitherto provided.

With the objectindicated, the invention consists in a pneumatic power hammer of the double acting reciprocating air current type in which the pump is made capable of being used alternatively, according to the situation of. the controlling means firstly, as a pump driving the hammer on the reciprocating air current principle and secondly, as a compressor compressing air into a reservoir for the purpose of striking single blows and holding the hammer down and having a clearance or clearances provided in or in connexion with the pump to govern the ultimate pressure or pressures attained. The invention consists further in such a hammer having a controlling means contrived in such a way, according to the requirements contemplated in a construction, that, when it is in one position air passes to and fro between the pump cylinder and the hammer cylinder in the usual way to produce hammering, when in a second position the pump acts as a compressor compressing air into a reservoir and into the bottom of the hammer cylinder to hold the hammer up and when in a third position, while the pump is still pumping into the reservoir the reservoir is put into communication with the top of the hammer cylinder and the bottom of the hammer cylinder is put into communication with the atn'iosphere and a single dead blow is struck, or, that while capable of being put in such three positions, it can also be placed in an additional position in which a by-pass is opened up between the top and bottom of the pump cylinder to throw the hammer out of action. The invention consists further in such a hammer contrived so that one end of the pump only is used for supplying compressed air to the reservoir at a suitable pressure for striking single blows and the other end is used for pumping air into the bottom of the hammer cylinder at a pressure suitable for holding the hammer up. The invention consists further in a hammer contrived so that the controlling means as it is moved from one end of its range to the other controls the hannner in the sequence following first, holding up, second single blow, third, not working, fourth, self acting blows and also in other features hereinafter to be indicated and set forth in the claims.

By way of illustration two methods of carrying the invention into effect are shown in the accompanying drawings which show hammers so far as is necessary for the understanding of the construction and Working.

Fi g. 1 is a general elevation of a complete hammer. Fig. 2 is a vertical section showing the controlling means of a hammer in which both ends of the pump are used to supply the reservoir, the controlling meansbeing shown in one position and Figs. 3, 4 and 5 are fragmentary vertical sections showing the controlling means in other positions. Fig. 6 is a vertical section showing the controlling means of a hammer in which the top and bottom of a oump are used separately, the one to fill t e reservoir for i anna use in striking single blows and holding down and the other to pump air into the bottom of the hammer cylinder for holding the hammer up, the controlling means being shown in one position. Fig. 7 is a horizontal section on the plane indicated by the line 7-7 in Fig. 6 and Figs. 8, 9 and 10 are fragmentary vertical sections showing the controlling means in other positions.

The same numerals of reference are employed to indicate corresponding parts in r all the figures.

Figs; 2, 3, l. and 6, S, 9, show sections of the valve and valve chest and part sectionof the pump and hammer cylinders and connecting passages. In all the figures for cl'earness ports in the valve chest and valve areshown only inthe part cut by the plane of section although they are each formed as a series of openings extending around the valve chest or the valve as the case may be,

In the hammershown in Figs. 1 and 2, adouble acting hammer cylinder 4 and pis ton 5 and double acting pump cylinder 6 and piston 7 are provided with a valve chest 8 between them in which is a valve 9. The cylinders 4 and 6 are supported by a standard or'frame of any suitable formation and are provided at the top with covers 400, 600 closing them. At the bottomthe cylinder 4 is closed by a cover allowing passage to the piston rod 500 of 1' he piston 5 and means. such as a stuffing box with packing or elastic rings for preventing leakage of air from, occurring around the piston rod 500. The cylinder 6 at the bottom allows passage to a sleeve on the piston 7. In the working of the hammer the piston 7 is reciprocated in any suitable way for example by a pitman 799 connected with it and a crank or eccentric 701 revolved by any appropriate means. The piston is connected by its piston rod 500 with. a tup or hammer head 200 of any suitable kind towork towards and away from a suitable opposed part for example, an anvil 300. Inlet valves 601, 602 are provided in connexion with each end of the pump cylinder 6. The pump cylinder 6 is connected with the valve chest 8 at the top and bottom respectively by the passages 10;

11. The'hammer cylinder 4 is likewise connected with the valve chest 8 at the top by the two passages 12 and 13 and at the bottom by the passage 14. There is also a res ervoir 15 in connexion with the valve chest 8.

The valve chest8 is formed of two tubes 16, 17 inserted inv the main cylinder casting. These tubes 16, 17 have ports 18, 19, 20, 21, 22, 23, 24,25,26, which communicate with the various passages and chambers as shown in the drawing.

The piston valve 9 for controlling these ports 18, 19, 20, 21, 22, 23, 24, 25, 26 is composed of three parts 27, 28, 29 strung together on a central spindle 30 movable up and down as desired, as for example by a suitable hand lever 101 or foot lever and has pistons 31. 32, 34-, 36, 3'7, 38 and 39, which are formed of appropriate thicle ness and disposed at appropriate distances apart in relation to the ports 18, 19, 2t), 2!. 22, 23, 24, 26 in the manner clearly indicated in Fig. 2.

The valve 9 has a central passage 40 connected by radial passages 41 to the circumference of the piston 31. by a radial passage 42 with the circumference of the piston as and by holes 43 with the reservoir .15. The piston 32 has holes from the upper to the lower face. Each of the pistons 34. 36 has ports extending from an annular *avity to the circumference and also holes extending from one face to the other closed against the passage of air in one direction by means of a one-way valve 44 or 45, in the form of an annular metal disc under the influence of a spring. The piston 38 has a pas sage from the upper to the lower face. The piston 31 has oblique passages extending to the upper face from parts near thelower edge of the circumference. In the control of the hammer the valve 9 is moved up and down vertically and as the arrow 46 is sup-- posed to move with the valve 9 the main regulating positions will be indicated in Fig. 2 by the horizontal lines marked 47, 49. 49. and 50 corresponding to the positions in which the controlling means are shown in Figs. 2. 3, 1 and 5.

In the position 47 in which the valve 9 is shown in Fig. 2 of the drawing, communication is open between the ports 20, 19 and between the ports 24, 25. As the pump rcciprocates therefore air will pass to and fro between thetop of the pump cylinder (3 and the top of the hammer cyliiuler I- through the ports 20, 19 and similarly air will pass to and fro between the bottmn of the pump cylinder 6 and the bottom of the hammer cylinder 4, through the ports 24. 25 "the other ports being out of use. In this condition. the hammer will be giving full blow and be self acting. This position of the valve 9 therefore is called the full working or self acting position.

If the valve 9 be now raised to the position shown in Fig. 3 that is till the arrow 46 comes level with the horizontal line 48, a communication or by-pass will be opened up between the top and bottom of the pump cylinder 6, so that as the piston 7 reciprocates air will pass to and fro through the )orts 20, 21 the reservoir 15 and the ports 23, 25 The air will therefore not he forced into the hammer cylinder 4 at all. This position therefore is called the not working" position. lVhen the valve 9 is between the positions 4-7 and 18 the ports 21, 23 will ldll be partly open. and a reduced blow will be obtained. I

If the valve 9 be now raised to its top position shown in Fig. 5 in which the arrow 46 corresponds with the line 50 descent of the pump piston '7 will cause air to be passed through the port 24 and through the oneway valve 45 and the port into the reservoir 15. Similarly on the upstroke of the pump piston 7 air will pass through the port 20, the one-way valve 44 and the port 21, into the reservoir 15. This process will continue until the pressure in the reservoir 15 is equal. to the ultimate pressure attained at the ends of the cylinder 6. which is governed by the clearance in the cylinder 6 passages 10, 11 and other spaces in connexion with it. In this position also the compressed air from the reservoir 15 enters the lower end of the hammer cylinder 4 from the central passage 40 through the radial passage 42 and forces the hammer up, the air from the upper end of the hammer cylinder 4 being expelled to the outside atmosphere through the port 18 and the oblique passages in the piston 31.

If the valve 9 now be lowered to the posi tion shown in Fig. 4 that is till the arrow 46 is opposite the horizontal line 49 it will be seen that the conditions as far as the pump are concerned remain unchanged but that the lower end of the hammer cylinder 4 is now open to the atmosphere by means of the port 25, vertical passage in the piston 38, and port 26 and the top of the hammer cylinder 4 is put into communication with the reservoir 15 through the radial ports 41 and the central passage 40 and holes 43. The'hammer thus strikes a dead blow on the anvil and remains there. This therefore is called the single blow and hold-down po sition. By the valve 9 being put in an intermediate position between those indicated by the lines 50 and 49 more gentle blows or gradual lowering of the hammer can be obtained.

While so far as concerns the general construction, disposition and mounting of the hammer cylinder 4, pump piston 6 and valve chest 8 and the construction and operation of the pump piston 7 and hammer piston 5 and the parts connected therewith the description already given herein in reference to the hammer shown in Fig. 2, applies equally to the hammer shown in Figs. 6 and 7, in the hammer shown in Figs. 6, 7, 8, 9 and 10 the valve chest 8 is formed with ports 51, 52, 53, 54, 55, 56, 57, 58 the ports 51 communicating with the passage 13, the ports 52 communicating with the reservoir 15, the ports 53, 54 communicating with the passage 10, the ports 55, 56 communicating with the passage 11 and the ports 57 58 communicating with the passage 14. The valve 9 which is formed in parts 59, 60, 61, 62, 63, 64, threaded on a spindle 30 is provided with pistons 66, 67, 68, 69, 70, 71, '72, 73, 74. The pistons 66 69 and 73 are solid pistons. The pistons 67, 70, 72 and 74 are formed with longitudinal passages always open and the pistons 68, 71 are provided with holes from one face to the other and valves 44, 45 for closing them against the passage of air in one direction. In the casting between the cylinders 4, 6 a clearance chamber 75 is formed in communication with the interior of the valve chest 8 by means of the lower and upper ends of the tubes 16, 17 respectively. The positions and sizes of the ports 51, 52, 53, 54, 55, 56, 57 and 58 and the length or thickness of the several pistons and their disposition in relation to the ports are clearly indicated in Fig. 2. As in the description already given of Fig. 2, the arrow 46 in Fig. 6 is supposed to move with the valve 9 and the main regulating positions are indicated by the horizontal lines marked 47, 48, 49, 50 which have the same significance as in Fig. 2.

In the position indicated by the line 47 and shown in Fig. 8, the ports 53, 51, 56 and 57 are open and the air passes to and fro between the pump cylinder 6 and the hammer cylinder 4 in the usual way to produce hammering. The ports 52, 54, 55 and 58 being then closed.

In the position indicated by the line 48 and shown in Fig. 6, the pump is thrown out of action by the opening of a bypass through the ports 54, 55 and the clearance chamber 75 between the top and bottom of the pump cylinder 6 and the other ports are out of use, the hammer then remaining down by its weight.

By the valve 9 being placed between the positions indicated by the lines 48 and 47 blows of varying force may be obtained.

If the valve 9 be moved to present the arrow 46 to the line 50 and shown in Fig. 9, the upper end of the pump is used as a compressor passing compressed air through the one-way valve 44 and port 52 into the reser voir 15 where it is stored, the ultimate pressure being governed by the clearance in or in connexion with the top of the pump cylinder 6. In this position also the bottom of the pump passes compressed air through the one-way valve 45 into the bottom of the hammer cylinder 4 for the purpose of holding the hammer up and the top of the hammer cylinder 4 is open to the atmosphere through the ports 51. In this position of the valve 9 the pressure in the lower part of the hammer cylinder 4 is limited by the clear ance chamber 75 which is in free communication with the lower end of the pump cvlinder 6 through the ports 55 and 56 and the pressure in this case may conveniently be considerably lower than the pressure in the reservoir 15.

If the valve 9 be moved to present the arrow 46 to the line 49 and shown in Fig. 10

the reservoir ,15 air then passing through the ports 52, 51 from the reservoir 15 to force the hammer down.

For a single blow to be struck the valve 9 is placed with the arrow 46 opposite the line 50 and then moved to present the arrow L6 to the line 49 and for holding down is allowed to remain with the arrow 46 opposite the line 49, so that the pump piston 7 may continue to pump air into the top of -.the hammer cylinder 4 up to limit of pressure determined by the space then in communication with the top of the pump cylinder 6.

By the valve 9 being put in an intermedi- -=ate position between those indicated by the lines 50'and 49 more gentle blows or gradual lowering of the hammer can be obtained.

It will be, seen that in the case of each of the hammers illustrated in the drawings, the disposition of the valve is very con venient and the movement of the valve 9 in stages from the position indicated by the line 47 to the position indicated by the line 50 brings about control of the operations of the hammer according to the very advantageous manner or sequence first, holding up, second, single blow, third, not workingl, fourth, self acting blows. By moving the valve within this range quickly or slowly any desired result may be obtained light or heavy blows either singly or self acting, or the hammer can be held up or held down or lowered gently on to the work, the change from one operation to another being easy and convenient.

In the construction of hammers according to this invention details may vary in different cases.

What I do claim as my invention and de sire to secure by Letters Patent is i 1. In a pneumatic power hammer of the double acting reciprocating air current type, a double acting hammer cylinder, a double acting pump cylinder with clearances for limiting the pressure, conneXions between the cylinders, areservoir for air to be put into connexion with the pump cylinderand hammer cylinder, and means for controlling the connexions between the pump cylinder and the hammer cylinder and between each of them and the reservoir, whereby the. pump is used alternatively, firstly, as a pump driving the hammer on the reciprocating air current principle and secondly, as a compressor compressing air into a reservoir for the purpose of striking single blows and continuing compression for holding the hammer down.

2. In a pneumatic power hammer of the double acting reciprocating air current type,a double acting hammer cylinder, a double acting pump cylinder with clear ances for limiting the pressure, connexions between the cylinders, a reservoir for air to be put into connexion with the pump cylinder and hammer cylinder and means for controlling the connexions between the pump cylinder and the hammer cylinder and between each of them and the reservoir, whereby in one situation of the controlling means, air passes to and fro between the pump cylinder and the hammer cylinder in the usual way to produce hammering, in a second situation the pump acts as a compressor compressing air into the bottom of the hammer cylinder to hold the hammer up and into the reservoir and, in a third situation whilst the pump is still pumping into the reservoir, the reservoir is put into communication with the top of the hammer cylinder and the bottom of the hammer cylinder is put into communication with the atmosphere to strike a single dead blow and to hold the hammer down.

3. In a pneumatic power hammer of the double acting reciprocating air current type, a double acting hammer cylinder, a double acting pump cylinder with clearances for limiting the pressure, conncxions between the cylinders, a reservoir for air to be put into connexion with the pump cylinder and hammer cylinder and means for controlling the connexions between the pump cylinder and hammer cylinder and between each of them and the reservoir whereby, in one situation of the controlling means, air passes to and fro between the pump cylinder and the hammer cylinder in the usual way to produce hammering, in a second situation, the pump acts as a compressor compressing air into the bottom of the hammer cylinder to hold the hammer up and into the reservoir, in a third situation, whilst the pump is still pumping into the reservoir, the reservoir is put into com munication with the top of the hammer cylinder and the bottom of the hamn'ier cylinder is put into communication with the atmosphere to strike a single dead blow and to hold the hammer down, and, in a fourth situation, a bypass is opened up between the two ends of the pump cylinder to throw the hammer out of action.

4:. In a pneumatic power hammer of the double acting reciprocating air current type, a double acting hammer cylinder, a don le acting pump cylinder with clearances for limiting the pressure, connexions between the cylinders, a reservoir for air to be put into connexion with the pump cylinder and hammer cylinder and means for controlling the connexions between the pump cylinder and the hammer cylinder and between each of them and the reservoir, whereby the pump is used alternatively, firstly, as a pump driving the hammer on the reciprocating air current principle and, secondly, as a compressor with the one end of the pump only used for supplying compressed air to a reservoir at a suitable pressure for striking single blows and holding the hammer down and the other end used for pumping air into the bottom of the hammer cylinder at a suitable pressure for holding the hammer up.

5. In a pneumatic power hammer of the double acting reciprocating air current type, a double acting hammer cylinder, a double acting pump cylinder with clearances for limiting the pressure, connexions between the cylinders, reservoir for air to be put into connexion with the pump cylinder and hammer cylinder, and means for controlling the connexions between the pump cylinder and the hammer cylinder and between each of them and the reservoir, whereby, in one situation of the controlling means, air passes to and fro between the pump cylinder and the hammer cylinder in the usual way to produce hammering, in a second situation, the pump acts as a compressor with one end of the pump only used for supplying compressed air to the reservoir at a suitable pres sure for striking single blows while the other end is used for pumping air into the bottom of the hammer cylinder at a suitable pressure for holding the hammer up and, in a third situation, the reservoir is put into communication with the, top of the hammer cylinder and the bottom of the hammer cylinder is put into communication with the atmosphere to strike a single dead blow and to hold the hammer down.

6. In a pneumatic power hammer of the double acting reciprocating air current type, a double acting hammer cylinder, a double acting pump cylinder with clearances for limiting the pressure, connexions between the cylinders, a reservoir for air to be put into connexion with the pump cylinder and hammer cylinder and means for controlling the connexions between the pump cylinder and the hammer cylinder and between each of them and the reservoir, whereby, in one situation of the controlling means, air passes to and fro between the pump cylinder and the hammer cylinder in the usual way to produce hammering, in a second situation, the pump acts as a compressor with one end of the pump only used for supplying compressed air to the reservoir at a suitable pressure for striking single blows while the other end is used for pumping air into the bottom of the hammer cylinder at a suitable pressure for holding the hammer up, in a third situation, the reservoir is put into communication with the top of the hammer cylinder and the bottom of the hammer cylinder is put into communicatioi'i with the atmosphere to strike a single dead blow and to hold the hammer down and, in a fourth situation, a by-pass is opened up between the two ends of the pump cylinder to throw the hammer out of action.

7. In a pneumatic power hammer of the double acting reciprocating air current type, a double acting hammer cylinder, a double acting pump cylinder with clearances for limiting the pressure, connexion between the cylinders, a reservoir for air to be put into connexion with the pump cylinder and harm ner cylinder and means for controlling the connexions between the pump cylinder and the hammer cylinder and between each of them and the reservoir and movable from one end to the other of a range of movement to control the hammer in the following sequence: first, holding up through air compressed by the pump acting on the bottom of the hammer piston, second, single blow through air compressed by the pump into the reservoir acting on the top of the hammer piston, third, not working through the opening up of a bypass between the two ends of the pump cylinder, fourth, self acting blow through the pump driving the hammer on the reciprocating air current principle.

8. In a pneumatic power hammer of the double acting reciprocating air current type, a double acting hammer cylinder, a double acting pump cylinder with clearances for limiting the pressure, connexions between the cylinders, a reservoir for air to be put into connexion with the pump cylinder and ham mer cylinder, means for controlling the connexions between the pump cylinder and the hammer cylinder and between each of them and the reservoir and movable from one end to the other of a range of movement, to control the hammer in the following sequence: first, holding up, through air compressed by one end of the pump acting on the bottom of the hammer piston, second, single blow through air compressed by the other end of the pump into the reservoir acting on the top of the hammer piston, third, not working through the opening up of a by-pass between the two ends of the pump cylinder, fourth, self acting blow through the pump driving the hammer on the reciprocating air current principle.

In testimony, that I claim the foregoing as my invention, I have signed my name this fourteenth day of July 1922.

HAROLD FLETCHER MASSEY. 

